1. Field of the Invention
The present invention relates to welding materials for low temperature steels, such as, 3.5% Ni steel, 5.5% Ni steel and 9% Ni steel which are used at low temperatures between -100.degree. and -196.degree. C.
2. Description of the Prior Art
As the welding material for 9% Ni steel and 5.5% Ni steel, Inconel alloys of 75 Ni-- 15 Cr series are used, and as the welding material for 3.5% Ni steel, austenite stainless steels, such as D308 or D316 and 35 Ni--16 Cr alloys are used. But all of these materials are of high cost because of the high nickel content and are often economically disadvantageous for manufacturing structures.
One of the objects of the present invention is to provide a welding material which improves the impact strength of welded portions of the low temperature steels at low temperatures from -100 .degree. to -196.degree. C and which is low in cost and is easy to handle.